1. Technical Field
This invention is directed toward a new camera design. More specifically, this invention is directed toward a camera design with an improved up look angle and an improved ability to calibrate a virtual center of projection.
2. Background Art
Video conferencing has become more popular in recent years. Various video conferencing camera systems have been developed for this purpose. In many video conferencing scenarios an omni-directional camera is placed in the middle of a conference room table. This camera captures images of the meeting participants sitting around the table for transmission to a remote site or later play back of the meeting for those unable to attend.
There are two general categories of omni-directional or panoramic video cameras: single sensor and multiple sensor designs. Single sensor omni-directional cameras use multiple mirrors to image a 360 degree horizontal field of view onto an image sensor. Single sensor designs are limited in resolution by the image sensor, and are typically more expensive than multi-sensor designs. Their resolution and frame rate are also typically limited. In addition, the curved mirror designs used in these single sensor designs have typically suffered from a limited depth of field. Multi-sensor designs do not have the aforementioned limitations of single sensor designs and are therefore typically preferable. These multi-sensor designs can often be difficult to calibrate and manufacture however.
In video recording multiple participants in a meeting for transmission or later playback, it is important to situate the camera in such a way that less of the conference room table is captured and more of the meeting participants are captured. This increases the efficiency with which the meeting data can be transmitted or archived.